Phi6 is a bacteriophage with a genome of three segments of dsRNA. Procapsids are produced in E. cold from plasmids carrying cDNA copies of genes 7, 2,4, and 1. These procapsids package and replicate viral RNA in vitro. Procapsids can be prepared with mutated or missing proteins. This sample has been previously sent to EMBL for cryo-TEM imaging. The images obtained from cryo-TEM or negative staining showed that the empty procapsids usually look like collapsed dodecahedra We believed the normal particle must expand during packaging of RNA. The macromolecular imaging by cryo-HRSEM at the IMR is valuable for us to view mutated Phi6 capsids. We expect to see structural changes in packaging mutants or during normal packaging.